<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
   <script>
       function Person(name='xiaoming',age='18'){
            this.name=name;
            this.age=age;
       }

       let rfg=new Person();
       console.log(rfg);


       let mon =new Person('xiaoli',19);
       console.log(mon);
   </script>
</body>
</html>